Dual centrifugal chiller

ABSTRACT

The present invention relates to a dual centrifugal chiller, and it is an object of the present invention to provide a dual centrifugal chiller which is configured so that a turbo chiller having two compressors, two evaporators and two condensers lowers the head of the compressors, and that the compressors are operated with the same heads. The above object can be accomplished by the provision of a dual centrifugal chiller in which chilled water passes through a first evaporator and then through a second evaporator, cooling water passes through a first condenser and then through a second condenser, a first compressor accommodating a refrigerant connects said first evaporator and said second condenser, and a second compressor accommodating a refrigerant connects said second evaporator and said first condenser.

TECHNICAL FIELD

The present invention relates to a dual centrifugal chiller, more particularly to a dual centrifugal chiller which lowers heads of compressors among constituent elements of two independent centrifugal chillers and is configured so that compressors are operated with the same head.

BACKGROUND ART

A typical centrifugal chiller is provided with a compressor, an evaporator, a condenser and an expansion valve, and it circulates refrigerants so that the heat is transferred from the evaporator to the condenser through the compressor.

As a way to increase the capacity of the centrifugal chiller configured as mentioned above, capacities of individual components may be enhanced. As another way to increase the capacity of the centrifugal chiller, two centrifugal chillers may be connected with each other. The chiller in which the two centrifugal chillers are connected with each other is called the “dual centrifugal chiller”.

In a conventional dual centrifugal chiller, chillers are connected in a serial manner.

FIG. 1 is a schematic illustration showing a serial type of a conventional dual centrifugal chiller.

As shown in FIG. 1, a serial type of a dual centrifugal chiller 10 comprises two evaporators 11, 22, two condensers 21, 22 and two compressors 31, 32. Chilled water of the evaporators flows along the path from a first evaporator 11 through a second evaporator 12 and again through the second evaporator 12 to the first evaporator 11. Further, cooling water of the condensers flows along the path from a first condenser 21 through a second condenser 22 and again through the second condenser 22 to the first condenser 21.

Furthermore, a first compressor 31 in which a refrigerant circulates connects the first evaporator 11 and the first condenser 21, and a second compressor 32 in which a refrigerant circulates connects the second evaporator 12 and the second condenser 22.

For example, according to the Korean Standard (KS), the temperature of the chilled water flowing into the first evaporator 11 is 12° C., and the temperature of the chilled water flowing out of the first evaporator 11 is 7° C. The temperature of the cooling water flowing into the first condenser 21 is 32° C., and the temperature of the cooling water flowing out of the first condenser 21 is 37° C.

Therefore, the head of the first compressor 31 is 32° C. (38° C.-6° C.), and the head of the second compressor 32 is 29.5° C. (36.75° C.-7.25° C.). The temperatures shown in FIG. 1 are the temperatures of the cooling water. The evaporator LTD is 1° C. and the condenser LTD is 1° C. Accordingly, the temperature of the refrigerant of the first compressor 31 is 6° C. when the temperature of the chilled water flowing out of the first evaporator 11 is 7° C., and the temperature of the refrigerant of the first compressor 31 is 38° C. when the temperature of the cooling water flowing out of the first condenser 21 is 37° C.

As such, the head of the first compressor 31 is relatively higher than that of the second compressor 32.

Accordingly, when two independent centrifugal chillers are used, a compressor of any one of the chillers has a relatively higher head and thus an independent compressor should be designed and produced. When the independent centrifugal chillers are made of the same compressors, it is advantageous in that design, mass production and post-management are easy. However, with the conventional configuration, it is difficult to utilize this advantage.

DISCLOSURE Technical Problem

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a dual centrifugal chiller which is configured so that a turbo chiller having two compressors, two evaporators and two condensers lowers the head of the compressors, and that the compressors are operated with the same heads.

Technical Solution

The above object can be accomplished by the provision of a dual centrifugal chiller in which chilled water passes through a first evaporator and then through a second evaporator, cooling water passes through a first condenser and then through a second condenser, a first compressor accommodating a refrigerant connects said first evaporator and said second condenser, and a second compressor accommodating a refrigerant connects said second evaporator and said first condenser.

In accordance with an embodiment of the present invention, said first evaporator and said second evaporator may be connected in a parallel manner, and said first condenser and said second condenser may be connected in a serial manner.

In accordance with another embodiment of the present invention, said first evaporator and said second evaporator may be connected in a serial manner, and said first condenser and said second condenser may be connected in a parallel manner.

In accordance with still another embodiment of the present invention, said first evaporator and said second evaporator may be connected in a parallel manner, and said first condenser and said second condenser may be connected in a parallel manner.

ADVANTAGEOUS EFFECTS

A dual centrifugal chiller of the present invention having two evaporators, two compressors and two condensers can lower heads of individual compressors and maintain them at the same levels so that an optimum performance of the compressors can be realized.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustration of a serial type of a conventional dual centrifugal chiller;

FIG. 2 is a schematic illustration showing a dual centrifugal chiller according to a first embodiment of the present invention, in which two evaporators are connected in a parallel manner and two condensers are connected in a serial manner;

FIG. 3 is a schematic illustration showing a dual centrifugal chiller according to a second embodiment of the present invention, in which two evaporators are connected in a serial manner and two condensers are connected in a parallel manner;

FIG. 4 is a schematic illustration showing a dual centrifugal chiller according to a third embodiment of the present invention, in which two evaporators and two condensers are all connected in a parallel manner; and

FIG. 5 is a schematic illustration showing a comparative example of the dual centrifugal chiller shown in FIG. 4.

BEST MODE

Hereinafter, preferred embodiments of a dual centrifugal chiller according to the present invention will be described with reference to the accompanying drawings. Although the embodiments of the invention are described with reference to the drawings, those skilled in the art will appreciate that each of them is described as example only and the scope and spirit of the invention and a core constitution thereof are not limited thereby.

FIG. 2 is a schematic illustration showing a dual centrifugal chiller according to a first embodiment of the present invention, in which two evaporators are connected in a parallel manner and two condensers are connected in a serial manner. FIG. 3 is a schematic illustration showing a dual centrifugal chiller according to a second embodiment of the present invention, in which two evaporators are connected in a serial manner and two condensers are connected in a parallel manner. FIG. 4 is a schematic illustration showing a dual centrifugal chiller according to a third embodiment of the present invention, in which two evaporators and two condensers are all connected in a parallel manner. And, FIG. 5 is a schematic illustration showing a comparative example of the dual centrifugal chiller shown in FIG. 4.

First Embodiment

As shown in FIG. 2, in a dual centrifugal chiller 101 according to a first embodiment, a first evaporator 111 and a second evaporator 112 are connected in a parallel manner. Chilled water flows in a one end of the first evaporator 111 connected in a parallel manner and flows out of the other end of the first evaporator 111, after which the flown-out chilled water flows in a one end of the second evaporator 112 and out of the other end of the second evaporator 112 via the second evaporator 112.

A first condenser 121 and a second condenser 122 are connected in a serial manner, and cooling water flows in the second condenser 122 via the first condenser 121 and then flows out of the second condenser 122.

The first compressor 131 is connected to the first evaporator 111 and to the second condenser 122, and a refrigerant of the first compressor 131 transfers the heat of chilled water of the first evaporator 111 and the heat of cooling water of the second condenser 122 to each other as it circulates. The second compressor 132 is connected to the second evaporator 112 and the first condenser 121, and a refrigerant of the second compressor 132 transfers the heat of chilled water of the second evaporator 112 and the heat of cooling water of the first condenser 121 to each other as it circulates.

The temperature of the chilled water flowing in the first evaporator 111 is 12° C., the temperature of the chilled water flowing out of the second evaporator 112 is 7° C., the temperature of the cooling water flowing in the first condenser 121 is 32° C., and the temperature of the cooling water flowing out of the second condenser 122 is 37° C.

Accordingly, considering that the evaporator LTD is 1° C. and the condenser LTD is 1° C., the head of the first compressor 131 is 29.5° C. (38° C.-8.5° C.), and the head of the second compressor 132 is 29.5° C. (35.5° C.-6° C.).

Second Embodiment

As shown in FIG. 3, in a dual centrifugal chiller 102 according to a second embodiment, a first evaporator 211 and a second evaporator 212 are connected in a serial manner, and chilled water flows in the second evaporator 212 via the first evaporator 211 and then flows out of the second evaporator 212 via the second evaporator 212.

The first condenser 221 and the second condenser 222 are connected in a parallel manner. Cooling water flows in a one end of the parallel-connected first condenser 221 and then flows out of the other end of the first condenser 221, after which the flown-out cooling water flows in a one end of the second condenser 222 and then flows out of the other end of the second condenser 222 via the second condenser 222.

The first compressor 231 is connected to the first evaporator 211 and to the second condenser 222, and a refrigerant of the first compressor 231 transfers the heat of chilled water of the first evaporator 211 and the heat of cooling water of the second condenser 222 to each other as it circulates. The second compressor 232 is connected to the second evaporator 212 and the first condenser 221, and a refrigerant of the second compressor 232 transfers the heat of chilled water of the second evaporator 212 and the heat of cooling water of the first condenser 221 to each other as it circulates.

The temperature of the chilled water flowing in the first evaporator 211 is 12° C., the temperature of the chilled water flowing out of the second evaporator 212 is 7° C., the temperature of the cooling water flowing in the first condenser 221 is 32° C., and the temperature of the cooling water flowing out of the second condenser 222 is 37° C.

Accordingly, considering that the evaporator LTD is 1° C. and the condenser LTD is 1° C., the head of the first compressor 231 is 29.5° C. (35.5° C.-6° C.), and the head of the second compressor 232 is 29.5° C. (38° C.-8.5° C.).

Third Embodiment

As shown in FIG. 4, in a dual centrifugal chiller 103 according to a third embodiment, a first evaporator 311 and a second evaporator 312 are connected in a parallel manner. Chilled water flows in a one end of the first evaporator 311 connected in a parallel manner and flows out of the other end of the first evaporator 311, after which the flown-out chilled water flows in a one end of the second evaporator 312 and out of the other end of the second evaporator 312 via the second evaporator 312.

The first condenser 321 and the second condenser 322 are connected in a parallel manner. Cooling water flows in a one end of the parallel connected first condenser 321 and then flows out of the other end of the first condenser 321, after which the flown-out cooling water flows in a one end of the second condenser 322 and then flows out of the other end of the second condenser 322 via the second condenser 322.

The first compressor 331 is connected to the first evaporator 311 and to the second condenser 322, and a refrigerant of the first compressor 331 transfers the heat of chilled water of the first evaporator 311 and the heat of cooling water of the second condenser 322 to each other as it circulates. The second compressor 332 is connected to the second evaporator 312 and the first condenser 321, and a refrigerant of the second compressor 332 transfers the heat of chilled water of the second evaporator 312 and the heat of cooling water of the first condenser 321 to each other as it circulates.

The temperature of the chilled water flowing in the first evaporator 311 is 12° C., the temperature of the chilled water flowing out of the second evaporator 312 is 7° C., the temperature of the cooling water flowing in the first condenser 321 is 32° C., and the temperature of the cooling water flowing out of the second condenser 322 is 37° C.

Accordingly, considering that the evaporator LTD is 1° C. and the condenser LTD is 1° C., the head of the first compressor 331 is 29.5° C. (38° C.-8.5° C.), and the head of the second compressor 332 is 29.5° C. (35.5° C.-6° C.).

Comparative Example

In a dual centrifugal chiller 104 shown in FIG. 5, chilled water of evaporators passes through a first evaporator 411 and a second evaporator 412, and cooling water of condensers passes through a first condenser 421 and a second condenser 422. A first compressor 431 is connected to the first evaporator 411 and the first condenser 421, and a second compressor 432 is connected to the second evaporator 412 and the second condenser 422.

The temperature of the chilled water flowing in the first evaporator 411 is 12° C., the temperature of the chilled water flowing out of the second evaporator 412 is 7° C., the temperature of the cooling water flowing in the first condenser 421 is 32° C., and the temperature of the cooling water flowing out of the second condenser 422 is 37° C.

Accordingly, considering that the evaporator LTD is 1° C. and the condenser LTD is 1° C., the head of the first compressor 431 is 27° C. (35.5° C.-8.5° C.), and the head of the second compressor 432 is 32° C. (38° C.-6° C.).

As such, heads of the first and second compressors 131, 132, 231, 232, 331, 332 according to the first through third embodiments are all 29.5° C. In contrast, the head of the first compressor 431 of the comparative dual centrifugal chiller is 27° C., and the head of the second compressor 432 is 32° C.

In the dual centrifugal chiller having two evaporators, two condensers and two compressors as described above, the head of a compressor may be different according to individual arrangement configurations.

Further, according to the present invention, although not shown in the drawings, in a state where a first evaporator and a second evaporator are connected in a serial manner and a first condenser and a second condenser are connected in a serial manner, a first compressor may be connected to the first evaporator and the second condenser, and a second compressor may be connected to the second evaporator and the first condenser. In this case, the first compressor which connects the first evaporator and the second condenser, and the second compressor which connects the second evaporator and the first condenser can be cross-connected in a state where they are relatively long in their length. 

1. A dual centrifugal chiller in which chilled water passes through a first evaporator and then through a second evaporator, cooling water passes through a first condenser and then through a second condenser, a first compressor accommodating a refrigerant connects said first evaporator and said second condenser, and a second compressor accommodating a refrigerant connects said second evaporator and said first condenser.
 2. The dual centrifugal chiller according to claim 1, wherein said first evaporator and said second evaporator are connected in a parallel manner, and said first condenser and said second condenser are connected in a serial manner.
 3. The dual centrifugal chiller according to claim 1, wherein said first evaporator and said second evaporator are connected in a serial manner, and said first condenser and said second condenser are connected in a parallel manner.
 4. The dual centrifugal chiller according to claim 1, wherein said first evaporator and said second evaporator are connected in a parallel manner, and said first condenser and said second condenser are connected in a parallel manner. 